1. Field of the Invention
The present invention relates to a method of recycling organic scrap, particularly to a method of utilizing a catalytic reaction to recycle organic scrap.
2. Description of the Related Art
Owing to massive energy consumption, energy resource is being exhausted gradually. Further, in 2005, the Kyoto Treaty to UNFCCC (the United Nations Framework Convention on Climate Change) entered into force, and the regulations of controlling carbon dioxide emission has come to work then. Now, many nations have regarded energy-regeneration as a high-priority target. Therefore, recycling scrap is no more only for environmental protection but is also for energy regeneration. Scrap is no more a useless, or even harmful waste but may be an economic-efficient resource.
The plastic is often used as the insulation materials of cables, current/potential transformers, and transformers include: thermoplastic PE (polyethylene), thermosetting Si-XLPE (silane cross-linked polyethylene), and thermosetting Epoxy resin. Part of it is often used filling grease (usually petroleum naphtha) to protect it from humidity and water. Those industrial scraps come from the abovementioned parts should be recycled; however, the recycling process not only should be environment-friendly but also should be able to produce high-quality regenerated energy, and clean metals with undamaged mechanical and electrical properties.
In the conventional treatments, current/potential transformers, transformers and cables, which contain thermosetting PE or thermosetting resin, and products, which contain composite material, are essentially buried or burned. The conventional treatments primarily adopt mechanically-processing methods to separate insulation materials from metals in a destructive way. Among those mechanically-processed scraps, the organic scraps of high plasticity and high moldability, such as PE and PVC scraps, are to be recycled; the contaminated scraps, such as grease- or paint-containing scraps, are not recycled but abandoned since the properties thereof will be influenced by contaminants; the metals recycled from the mechanically-processed metallic scraps will be contaminated by the insulation materials sticking to the metal surface during the recycling process. Owing to low flowability and inferior moldability, the thermosetting XLPE and Epoxy scraps are hard to recycle and will be buried or burned, which not only causes pollution but also disobeys the final objective of the sustainable development of UNFCCC.
At present, most of the commercialized technologies for recycling solid scrap adopt the thermal-cracking method, which cracks solid scrap into high-value-added heavy oil, light fuel oil, petroleum gas, and coke.
However, the conventional thermal-cracking method not only cannot process the scraps containing thermosetting plastic, paint, or grease but also has to heat the scraps to the temperature as high as more than 550˜600° C. The thermal conductivity of organic scrap is very low, therefore, the heating time will be very long, and the processing capacity is hard to promote. Thus, the conventional thermal-cracking method is relatively uneconomical. Besides, the coke generated by the conventional thermal-cracking method contains a very high proportion of oil; thus, it should be processed once more to meet safety and environmental-protection requirements. The conventional thermal-cracking method adopts a one-stage horizontal cracking furnace; the utilization rate of the conventional cracking furnace and the yield rate of the regenerated oil still have much room to improve. Furthermore, owing to gaseous or solid blocking, fires or explosions often take place in the conventional horizontal cracking furnace. Therefore, the conventional horizontal cracking furnace also has serious safety problems to overcome.